Agents and mineral oil lubricant compositions containing the same



Patented July 15, 1952 AGENTS AND MINERAL on.

LUBRICANT COMPOSITIONS CONTAINING THE SAME Herschel G.

Cantrell, Lansdowne, Pa., Corporation, Pittsburgh, Pa.,

Pennsylvaniav No Drawing Smith, Wallingford, and Troy L.

assignors to Gulf Oil a corporation of Application December 27, 1946,

Serial No. 718,902

12 Claims. 7 (Cl. 25246.6)

This invention relates to improvement agents and mineral oil lubricant compositions containing the same and, more particularly, it is concerned with improvement agents which confer improved antioxidant, corrosion-inhibiting and pressure-carrying properties on mineral oil lubricants.

It is recognized in the art that mineral oil lubricants are readily oxidized under service conditions thereby reducing the service life of internal combustion engines and steam turbines. A concomitant effect is corrosion of bearing surfaces. These problems become particularly acute when a highly refined paraffinic base mineral oil is employed as the lubricant.

In the lubrication of internal combustion engines of alltypes, particularly whensevere operating conditions are encountered, mineral lubricating oils frequently prove unsatisfactory because they tend to deposit varnish, gum and sludge on the engine surfaces, such as the cylinder walls, piston and rings, and also to induce present invention wherein an for mineral oil lubricants is prepared by heating an essentially parafiinic baselubricating oil with anhydrous aluminum chloride,'removing aluminum chloride from the reaction product, and reacting said product with phosphorus pentasulfide at an elevated temperature to incorporate phosphorus and sulfur therein.

We have found that the reaction product of phosphorus pentasulfide with an essentially paraffinic base lubricating oil which has been treated with aluminum chloride produces an improvement agent for'mineral oil lubricant comcorrosion of bearing materials thereby causing failure of the engine. These problems have become increasinglyserious because of the trend toward higher efficiency or higher power output per unit weight of engine, which resultsin conditions tending to accelerate the deteriorating influences on the mineral oil lubricant. The formation of so-called varnishes and sludges on engine surfaces is a result of oxidation effects on the lubricating oils. The presence of gums, varnishes and sludges is detrimental for many reasons. These substances tend to increase ring sticking and accelerate the formation of further deposits on piston surfaces and in fixed parts of the combustion chamber. The sludges formed in the crank case of the engine increase the rate of corrosion of bearing surfaces, especially of bearing alloys of the types now in use.

In steam turbines, the corrosion problem is' particularly acute because of the presence of water in the mineral oil lubricant, and in addition to hearing corrosion, rusting may also be encountered. I

It is an object of this invention, therefore, to prepare an improvement agent'which will obviate theoxidation and corrosion difficulties encountered in the use of mineral oil lubricants.

It is a further object of this invention to provide improved mineral oil lubricant compositions which are stable in storage and use and in which oxidation and corrosion effects are materially'inhibited. I

It is also an object of this invention to provide mineral oil lubricant compositions which have excellent pressure-carrying properties.

These and other objects are achieved by the hydrocarbon oils;

positions which is remarkably effective in inhibiting oxidation and corrosion and which, in addition, confers excellent pressure-carrying properties on mineral oil lubricants. Such improvement agents, as well as the mineral oil lubricant compositions containing them are believed to be novel and are considered parts of our invention.

In the production of our ,new agents, we have found that the treatment of an essentially paraffinic base lubricating oil stock with anhydrous aluminum chloride prior to reacting the product with phosphorus pentasulfide is critical. If the treatment with aluminum chlo ride is omitted anda parafiinic base lubricating oil is reacted with phosphorus pentasulfide, there is obtained a black, slud.ge-like product which is poorly soluble in mineral lubricating oils and which imparts such a degree of color to mineral oil lubricant compositions as to render them unmarketable. The same disadvantageous effects are observed when a hydrocarbon other than an essentially paraflinic base lubricating'oil is used as the initial material. On the other hand, when" anhydrous aluminum chloride is used to treat an essentially paraffinic base lubricating oil prior to its reaction with phosphorus pentasulfide, there 7 is obtained on subsequent reaction a clear, light'-' aluminum chloride treatment are not fully un- I derstood. It is known in the art that the treatment of hydrocarbon oils with anhydrous alu- V minum chloride tends to cause isomerization'and an effective decrease in the unsaturation'of such It is also knownthat aluminum chloride treatment ofhigher boiling hydrocarbons under drastic conditions converts such hydrocarbons into lower boiling "products. The extent of any. or all of these reactions in improvement agent 7 improvement minimum our process is unknown except that substantial conversion of'higher boilin hydrocarbons to lower boilingproductsisavoided. We do not desire tobe bound, therefore, by any theory of th action of anhydrous aluminum chloride on the.

parafiinic base lubricating oil reactant ,material.

However, the aluminum chloride treatment is Mid-continent or other parafiinic base crude! The lubricating oil is manufactured from such ed to the treated product and preferably, smaller amounts should be used. However, where the .,color of the product is. paramount, s'u'ch'blending may be undesirable The reaction with phosphorus pentasulfide is accomplished by adding from 2 to 20 per cent by weight of P285, preferably from-5 to per cent, to the aluminum chloride 1 cracking temperature of the oil will vary between crude in accordance with conventional methods and may be refined in accorance with methods known in the art. Theatment with aluminum chloride in accordance with our invention is accomplished by heating the essentially paraflinic base lubricating oil with from 1 .to percent ture of from 150 to 300 F.'while vigorously'agitating. The time of treatment may vary in accordance with the amount of aluminum chloride used and the temperature of treatment, longer of anhydrous aluminum chloride at a tempera- 3 times being required with less aluminum chloride and lower temperatures. In general, however, the treatment will be completed after 4 015 5 hours. In any event,'treatment is continued until a product is obtained which, when freed of aluminum chloride, will not form the black, difficultly soluble sludge-like product upon subsequent reaction with phosphorus pentasulfide. In

order to obtain the results of our invention, therefore, it is necessary, first, to emply an essentially parafiinic base lubricating oil; and, second, to treat said oil with aluminum chloride.

. After treatment with anhydrous aluminum chloride has progressed to the desired extent as set forth above, agitation is stopped and a sludge containing most of the aluminum chloride settles out from the main body of the oil. The sludge is drawn 01f and may be treated to recover aluminum chloride in-accordance with methods known tothe art. The supernatant body of the treated oil may contain further quantities of aluminum chloride finely dispersed therethrough, and in order to insure the removal of all aluminum chloride from the treated oil,'agitation with an adsorbent clay followed by filtration may be employed. Other known methods of removing aluminum chloride from the treated oil, such as agitation with dilute sulfuric acid, may also be employed as is understood in the art. At the higher temperatures of treatment with aluminum chloride, some conversion of the parafiinic base Oil to lower boiling products may take place.

However, even at the highest temperature stated, namely, 300 F., such conversion is slight; but

if desired, the product may be 'topped, that distilled to remove the lower boiling products" overhead and to recover as a residue the bulk of the aluminum chloride treated oil having a initial boiling point inthe range 490 'to'530F.

The essentially parafiinic base lubricating oil treated with aluminum chloride as disclosed I hereinabove is now ready for reaction with phosphorus 'pentasulfide. If desired, the aluminum chloride treated oil may be blended with some of. 1 the untreated charge stock without deleteriously affectingv the subsequent reaction. with phosph'orus pentasulfide, but ordinarily not more than about20' per cent of untreated oil should be add- 490 to 530 F. depending upon the particular oil used. During the course of the reaction with P285, hydrogen sulfide is evolved and phosphorus and sulfur become-incorported in the aluminum chloride treated 'oil.; When th evolution of-hy- Example I 1 Three thousandgallons of ,a solvent-refined dewaxed paraffinic base lubricating oil were charged .to a vessel equipped. with an agitator and means for heating and cooling, and agitated at 275 F. while adding 4 per centbyweight of anhydrous aluminum chloride; Agitation was then continued for 4 hours.. At the end of this time agitation was stopped and the bulk of the aluminum chloride settledin'a sludge at'the bottom of the vesselfThe sludge was withdrawn, and in order to remove any remain- 1 ing dispersed aluminum chloride in"'the. body 'of the oil, there was added 0.2 pound-per gallon of oil 'of. an adsorbent'clay, such as Super- Filtrol, and the mixture agitated at 210 F. The

mixture was then filtered and there was obtained in a yield of 84.1 percent by volume of the original charge an aluminum chloride treated oil free of aluminum chloride and having a viscosity index of 105. To '81 parts by volume of the treated oil, there were added 19 parts by volume of the original untreated oil and, of this mixture, 8550 parts by weight were placedinto a reaction vessel equipped with an agitator "and means for heating and cooling. Then 450 parts by weight of P285 were added withagitation at a temperature of 300 F. After all of the P285 had been added, the temperature was gradually raised to 450'F. A large volume of hydrogen sulfide was evolved and when evolution of hydrogen sulfide had nearly ceased, the temperature was raised to 500 F. to complete the reaction. The reaction with P28 fromthe time of its addition to the completion of the reaction took 8 hours. The reaction product was then cooled and discharged from the reaction vessel. The product had the following properties: l

: Gravity, API 26.1

Viscosity, SUV:

'F 651 210 73.4 Color, NPA 8.0

Sulfur, per cent Phosphorus, per cent V v 1.12 Neutralization No. Q

Another solvent. refined dewaxed: paraffinic base lubricating 'oil was treated with aluminum chloride under exactly the same conditions shown in Example I, except that '6 per centby weight 'of aluminum chloride was used.

Aluminum chloride was removed as in Example I, and-the treated oil reacted with 10 per cent by weight of phosphorus pentasulfide to yield a product having the following properties:

Gravity, API 21.7

Viscosity, SUV, 100 F. "1274 Sulfur, per cent 1.21

Phosphorus, per cent 2.63

Neutralization No. 18.8 Example III A prafiinic base oil was treated with 9 cent by weight of aluminum chloride under conditions as given in Example I. The aluminum chloridefree reaction product was then reacted with 10 per cent by weight of phosphoruspentasulfide under theconditions shown in Example :I to yield Example IV An aluminum chloride treated oil, as prepared in Example I, was treated with 10 per cent by weight of phosphorus pentasulfide at 450 F. for 6 hours to yield a product having the following properties:

Gravity, API 23.1 Viscosity, SUV, 100 F. 51684 Sulfur, per cent 1,4.41 Phosphorus, per cent "1.69

Neutralization No. 7 .13

' The phosphoruspent'asulfide" reaction products obtained in accordance 'with the preceding examples are excellent improvement agents for mineral oil lubricant compositions. They are readily soluble in "all types of mineral'oils, that is", paraffinic, naphthenic or mixed base mineral with mineral oils inproportions as high as =50 per cent'by weight or higher. This excellent solubility of our new improvement agents Jenables the preparation of concentrated solutions of improvement agents, which mayv then bev di- 1 luted down to. the proportion desired in the final mineral oil lubricant composition. stated,

our new improvement agents confer excellent a product having the. following properties:

Gravity, API-' 24.9 Viscosity, SUV, 100 F. 355 Sulfunpencentg 0.88 Phosphorus, per cent 0.90 Neutralization No. 0.56

oilsandyas a matter of fact, can-be. blended. V

inhibiting properties on the mineral lubricating oils with which they are incorporated. For these purposes, our'new improvement agents are generally addedto mineral oilsin minor amounts,

say frOmOI-pe'rjcent to 20 percent by weight [of the mineral'oil, sufiicient to confer improved pressure-carrying, ,antioxid'antjand' corrosioninhibiting properties on the mineral lubricating oil compositions. When our new improvement agents: are to be used for their antioxidant and corrosion-inhibiting effects, small proportions as low, as 0.1 per cent by weight are sufficient to effect the improvement. When extreme pressure properties are to be conferred on a lubricat ing'oil, higher proportions, as high as, 201 per cent, may conveniently be used. v r

If desired, our improvement agents 'may be neutralized with a metallic hydroxide or an amine prior to incorporation into a mineral oil lubricant. Particularly effective improvement agents are obtained when calcium}: magnesium or aluminum hydroxide are used for the neutralization. When amines are employed for the neutralization, it is preferred to ;e'mploylong chain alkyl amines; but aromatic amines aralkyl amines and cycloalkylamines, such as aniline benzylamineyand cyclohexylamine, may used with advantage, H

The following examples illustrate ,the' use of our new improvement agents to obtain improved mineral oil lubricant compositions:

Example V A lubricatingloil having excellent extreme also be pressure propertieswas prepared by blending 15 1 parts by weight of the improvement agent 'made' according to Example I and -parts by weight of a highly refined motor oil. A comparison of the properties of the improved lubricant and the base lubricant follows:

m a VI I; excellent turbineoil was prepared by blending 0.3 part bjnweight; of the improvement agent prepared in accordance; with Example III and 99.7 parts by weight of a refined turbine, oil

' base. The properties of the improved andg-unimproved turbine oils areas follows:

pressure-carrying,-. antioxidant and corrosion- Unimproved Tur- Improvel {Turbine Gravity: API 29.0 I 280 Viscosity, SUV 00F 407. .I 407 F 192.7 1 190.6 d '2.75" -"2.75 Method 257, Gulfz 1 Duration of Test: hr 48 48 Oil Bath Temperature: 7 347 I 347 Air Rate: cc./hr- 7 2,000 -2,000 Quantity of Oil 00.. 300v 300 Bearing Type Od-Ag Cu-Pb (id-Ag Cu-Pb Wt Change: Grams. -0. 1744 ,0.0188 --0.0 007j -|-0.0042 Wt. Change: Per cent '0.96 -0.08 +0.01 +0.02 Corrosion Test, v r

' 'ASTM 17065-44 T Distilled Water, j V F.,48Hr.SteelStrip:Appearanca rust. .ijB'right Area Rusted: Percent =100- q p v 0 Example Vrz "fianbkcellentimotoroil: SAE30fgrade; Q, Y prepared by blending 1 part by'weightof'the-iml ,we 'b 'Y w? F mt movement agent 'prepared'in accordance-with p s w compounded, 9 Example IV and 99 parts by 'weight of highly '6 invention is not limited .thereto but comprises all by the addition of the improvement agent.

' refined parafiinic SAEBO grade motor oil; Th mineral oil lubricantcompositions containing our properties of the improved anduriimproved new;improvementjagents, vsuch ,as, greases and Color, NPA' i 1. 75 2.0 Oxidation and Bearing Corrosion Test, v

Method 257, Gulf:

Duration of Test: hr..- 4 Oil'B'athTemperature: 347 F Air-Rate: .co./hr 2,000 7 Quantityof Oil: cc; n 1 300 Beating Type. J. Cd-Ag, Ou-Pb Wt, Change: Grams -0:054- 0. 0022 Wt. Changenpcrcen u O.Ql I 0, 01-

e I 7 f -ExdmpZefVHI v H .'What we claim;is:. V i i v 'An SAE 20-grade-motor oil Waspreparedby The f iP 'i fl m l f blendingv part by weigh-t of theqadditwegprfi agent for mineral 011 lubricants wh1ch comprises pared-according to Example'IV and 99 parts by heating miXture t g- Q ss t a and have a color which is-substantially unafiected 7 weight of a solvent refined SAE---20='grade motor .paraifinic base lubricating oil and, anhydrous- 011. The properties of theimproved and un maluminum chloride -at..a temperature ofirom proved mm o e s follows I 150 00 300 removing-aluminum chloride-from Unimproved Improved f:- Motor Oil MotorOil Gravityz APllne 29. 0 Viscosity-,'SUV: -l00"F .i. 337- Color, NPA' xidationa'nd Bearing Corr'm j e 4. 25;

sion TestfMethod 257, G111 1 Duration otTestzrhr 48 Oil Bath Tempcratu 347 Air Ratexcc; r-. i 2,.000. Quantity of Oil: (-0.. 1 e 300' Y 300 Bearign Type. Cd-Agj Oil-Pb' Od-Ag ,Cu-Ph Wt. Change: Grams 0.'2319 :-'00867' --.0. 00705-0. 0112 Wt. Change: percent l.28 -0. 38 ''0Z0l' 0.05

The :Oxidation and Bearing Corrosion Test, the. reaction product, and reactingsaid product Method 257, Gulf, referred to in the foregoing with-phosphorus'pentasulfide ata temperature of examples, is conducted as follows: An alloybearfrom;.-450 'F; to-amaximum temperature below ing shell of certain commonly used standard-dithe minimum;cracking'temperature of-said plQd- 'mensions is submerged-in 300cc. of'the oil-or oil uct to.incorporategphosphorus and sulfur-therein. composition in a 400 cc. Pyrex beaker and-heated 12.,iThe'process .of:epreparing an, improvement in a thermostatically controlled oil bath to 347 F. L .agentfor mineral. oil lubricants which comprises Air is then bubbled through the oil in contacts?' iheating''a mixture co sist ng. of angessentially with the bearingshellat the rate of 2000 cc. per paraflinic base lubricating oil and-fromwl tov20 hour. At theend of the 18 hours, the loss of -per cent byweightof anhydrous aluminum chloweight andconditionofthebearingshell'arederide at: a temperature of from 150 to 300 'F., 'termined', =the=bearing shell beingiwashed free of removing aluminum. chloride fromsaidproduct, oil and dried before weighing When fde'termin- 1 i "and-"reacting said product with from.2 to 20zper ing the eflectiveness of variouszfimp'rovement cent :by weight. .of phosphorus pentasulfide at:a agents, the 'usual procedurens'to run a "blank "temperature of from 4509B. to a maximum temtest simultaneously =with'the-oil composition 'beperature below thefminimum cracking :temperaing tested, employing for that purpose a sample ture of said product to incorporate phosphorus of the untreated. oil. Inthis test it is advantaand sulfur therein.

geous to employcommercial bearing shells/These V 3. The process of preparing an improvement shells comprise--a suitable metal backingfaced agentfor mineral oil lubricants which comprises with the alloy: bearing metal. In this Way, the; heating a mixture consisting of an essentially actual bearing 'faceis subjected to severedeteri parafiinic base lubricating oil and from 1 to 20 oration conditions. By comparisonof the results. .'..ipcr -.cent by Weight f anhydrous u um of such tests with actual service'-tests,-we--have chloride at a temperature of from 150 to 300 F., found them to be in substantial ar-geement :a'sitoh removing aluminum chloride from the reaction the suitability of particular lubricants; iproduct, distilling the reaction product and re- As is shown in the above examples, .thelad'dis covering as a residue a product having a minition of our newlimprovementagent -to mineral mum initial boiling point in the range 490 to oil lubricant compositions confersexc ellentprese; '-5 0 a d reacting S d p o ct W th om 5 sure-carrying, anti-oxidant and corrosion-ins, toll0'per cent by weight of phosphorus pentasul- 'hibiting pr erti s, At th sametimgethel omr fide at a temperature of from 450 F. to a maxipositions so obtained are stable in-storage'airduse' mm temperature below the minimum cracking temperature of said product to incorporate phosphorus and sulfur therein.

4. The process of preparing an improvement agent for mineral oil lubricants which comprises heating a mixture consisting of an essentially paraffinic base lubricating oil and from 1 to 20 per cent by weight of anhydrous aluminum chloride at a temperature of from 150 F. to 300 F., removing aluminum chloride from the reaction product, reacting said product with from 5 to per cent by weight of phosphorus pentasulfide at a temperature from 450 F. to a maximum temperature below the minimum cracking temperature of said product to incorporate phosphorus and sulfur therein, and dissolving the resultant product in a mineral lubricating oil.

5. The product obtainable by the process of claim 1.

6. The product obtainable by the process of claim 2.

7. The product obtainable by the process of claim 3.

8. The productobtainable by the process of claim 4.

9. A lubricant composition comprising a major amount of a mineral lubricating oil base and a minor amount, sufiicient to confer improved bearing corrosion-inhibiting properties on the composition, of the product obtainable by the process of claim 1.

10. A lubricant composition comprising a major amount of a mineral lubricating oil base and from 0.1 to 20 per cent by weight of the product obtainable by the processof claim 1.

11. A lubricant composition comprising a major amount of a highly refined paraffinic lubricating oil base and from 0.1 to 20 per cent of the product obtainable by the process of claim 3.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,242,260 Prutton May 20, 1941 2,315,529 Kelso Apr.-6, 1943 2,316,090 Kelso Apr. 6, 1943 2,367,468 Mixon et al. Jan. 16, 1945 

1. THE PROCESS OF PREPARING AN IMPROVED AGENT FOR MINERAL OIL LUBRICATING WHICH COMPRISES HEATING A MIXTURE CONSISTING OF AN ESSENTIALLY PARAFFINIC BASE LUBRICATING OIL AND ANHYDROUS ALUMINUM CHLORIDE AT A TEMPERATURE OF FROM 150* TO 300* F., REMOVING ALUMINUM CHLORIDE FROM THE REACTION PRODUCT, AND REACTING SAID PRODUCT WITH PHOSPHORUS PENTASULFIDE AT A TEMPERATURE OF FROM 450* F. TO A MAXIMUM TEMPERATURE BELOW THE MINIMUM CRACKING TEMPERATURE OF SAID PRODUCT TO INCORPORATE PHOSPHORUS AND SULFUR THEREIN. 